p5.js-web-editor/client/modules/App/App.js

import React from 'react';
import { connect } from 'react-redux';
import DevTools from './components/DevTools';

class App extends React.Component {
  constructor(props, context) {
    super(props, context);
    this.state = { isMounted: false };
  }

  componentDidMount() {
    this.setState({ isMounted: true });
  }

  render() {
    return (
      <div className="app">
        {this.state.isMounted && !window.devToolsExtension && process.env.NODE_ENV === 'development' && <DevTools />}
        {this.props.children}
      </div>
    );
  }
}

export default connect()(App);